Diagrams.Attributes

Diagrams may have attributes which affect the way they are rendered. This module defines some common attributes; particular backends may also define more backend-specific attributes.

Every attribute type must have a semigroup structure, that is, an associative binary operation for combining two attributes into one. Unless otherwise noted, all the attributes defined here use the Last structure, that is, combining two attributes simply keeps the second one and throws away the first. This means that child attributes always override parent attributes.

Color

Diagrams outsources all things color-related to Russell O'Connor's very nice colour package (http://hackage.haskell.org/package/colour). For starters, it provides a large collection of standard color names. However, it also provides a rich set of combinators for combining and manipulating colors; see its documentation for more information.

class Color c where

The Color type class encompasses color representations which can be used by the Diagrams library. Instances are provided for both the Colour and AlphaColour types from the Data.Colour library.

Methods

toAlphaColour :: c -> AlphaColour Double

Convert a color to its standard representation, AlphaColour.

fromAlphaColour :: AlphaColour Double -> c

Convert from an AlphaColour Double. Note that this direction may lose some information. For example, the instance for Colour drops the alpha channel.

Instances

Color SomeColor

(Floating a, Real a) => Color (Colour a)

(Floating a, Real a) => Color (AlphaColour a)

data SomeColor

An existential wrapper for instances of the Color class.

Constructors

forall c . Color c => SomeColor c

Instances

Color SomeColor

Typeable * SomeColor

someToAlpha :: SomeColor -> AlphaColour Double

Opacity

data Opacity

Although the individual colors in a diagram can have transparency, the opacity/transparency of a diagram as a whole can be specified with the Opacity attribute. The opacity is a value between 1 (completely opaque, the default) and 0 (completely transparent). Opacity is multiplicative, that is, opacity o1 . opacity o2 === opacity (o1 * o2). In other words, for example, opacity 0.8 means "decrease this diagram's opacity to 80% of its previous opacity".

Instances

Semigroup Opacity

AttributeClass Opacity

Typeable * Opacity

getOpacity :: Opacity -> Double

opacity :: HasStyle a => Double -> a -> a

Multiply the opacity (see Opacity) by the given value. For example, opacity 0.8 means "decrease this diagram's opacity to 80% of its previous opacity".

Converting colors

colorToSRGBA :: Color c => c -> (Double, Double, Double, Double)

Convert to sRGBA.

colorToRGBA :: Color c => c -> (Double, Double, Double, Double)

Deprecated: Renamed to colorToSRGBA.

Convert to sRGBA.

Line stuff

Cap style

data LineCap

What sort of shape should be placed at the endpoints of lines?

Constructors

LineCapButt

Lines end precisely at their endpoints.

LineCapRound

Lines are capped with semicircles centered on endpoints.

LineCapSquare

Lines are capped with a squares centered on endpoints.

Instances

Eq LineCap

Show LineCap

Default LineCap

Typeable * LineCap

data LineCapA

Instances

Eq LineCapA

Semigroup LineCapA

AttributeClass LineCapA

Typeable * LineCapA

getLineCap :: LineCapA -> LineCap

lineCap :: HasStyle a => LineCap -> a -> a

Set the line end cap attribute.

Join style

data LineJoin

How should the join points between line segments be drawn?

Constructors

LineJoinMiter

Use a "miter" shape (whatever that is).

LineJoinRound

Use rounded join points.

LineJoinBevel

Use a "bevel" shape (whatever that is). Are these... carpentry terms?

Instances

Eq LineJoin

Show LineJoin

Default LineJoin

Typeable * LineJoin

data LineJoinA

Instances

Eq LineJoinA

Semigroup LineJoinA

AttributeClass LineJoinA

Typeable * LineJoinA

getLineJoin :: LineJoinA -> LineJoin

lineJoin :: HasStyle a => LineJoin -> a -> a

Set the segment join style.

Miter limit

newtype LineMiterLimit

Miter limit attribute affecting the LineJoinMiter joins. For some backends this value may have additional effects.

Constructors

LineMiterLimit (Last Double)

Instances

Semigroup LineMiterLimit

Default LineMiterLimit

AttributeClass LineMiterLimit

Typeable * LineMiterLimit

getLineMiterLimit :: LineMiterLimit -> Double

lineMiterLimit :: HasStyle a => Double -> a -> a

Set the miter limit for joins with LineJoinMiter.

lineMiterLimitA :: HasStyle a => LineMiterLimit -> a -> a

Apply a LineMiterLimit attribute.